The Star Market in the Chestnut Hill shopping center will have a huge selection of Passover foods. If your dessert needs only to be pesadich but not necessarily come from a kosher bakery, you might try Rosie's in the same shopping center. Close to the Butcherie is Clear Flour, which also makes Passover desserts but probably won't have them this early and also will be pesadich but not kosher.

Agree- I have always gotten good things from Rosie's in the past. They like you to order, but they usually have some items available in case you don't. Also, I was at Whole Foods on Rt. 16 in Newton last night- they have some honey cakes and chocolate covered matzah. I think they will have more next week, which may not help you.